This study presents experimental results on the flow of magnetorheological grease (MRG) through microchannels. MR materials flowing through microchannels create microvalves. The flow is controlled by injecting the MRG through microchannels with controlled adjustable rates. To study the effect of different channel diameters and surface roughnesses, microchannels made of stainless steel, PEEK, and fused silica materials with nominal internal diameters ranging from 1 mm to 0.075 mm (75μm) are tested. A magnetic field is applied perpendicular to the microchannel flow and is controlled by an input electric current. The pressure drop of the flow is measured across the length of the microchannels. The dynamic pressure drop range and surface roughness effects are also discussed. The Herschel–Bulkley model for non-Newtonian fluid flow is employed to the experimental results with good agreement. The results show a significant pressure drop for different magnetic field strengths.

1.
Yoshida
,
K.
,
Kikuchi
,
M.
,
Park
,
J. -H.
, and
Yokota
,
S.
, 2002, “
Fabrication of Micro Electro-Rheological Valves (ER Valves) by Micromachining and Experiments
,”
Sens. Actuators, A
0924-4247,
95
, pp.
227
233
.
2.
Klein
,
J.
, and
Guckel
,
H.
, 1998, “
High Winding Density Micro Coils for Magnetic Actuators
,”
Microsyst. Technol.
0946-7076,
4
, pp.
172
175
.
3.
Wang
,
X.
, and
Gordaninejad
,
F.
, 2007, “
Magnetorheological Materials and Their Applications: A Review
,”
Intelligent Materials
,
M.
Shahinpoor
and
H. -J.
Schneider
, eds.,
Royal Society of Chemistry
,
Cambridge, UK
, pp.
339
385
.
4.
Papautsky
,
I.
,
Ameel
,
T.
, and
Frazier
,
A. B.
, 2001, “
A Review of Laminar Single-Phase Flow in Microchannels
,”
Proceedings of the ASME International Mechanical Engineering Congress and Exposition
,
New York, NY
, Nov. 11–16, pp.
1
9
.
5.
Judy
,
J.
,
Maynes
,
D.
, and
Webb
,
B. W.
, 2002, “
Characterization of Frictional Pressure Drop for Liquid Flows Through Microchannels
,”
Int. J. Heat Mass Transfer
0017-9310,
45
, pp.
3477
3489
.
6.
Sharp
,
K.
, and
Adrian
,
R.
, 2001, “
Shear-Induced Arching of Particle-Laden Flows in Microtubes
,”
ASME IMECE2001/MEMS-23879
, Vol.
2
,
ASME
,
New York
.
7.
Kormann
,
C.
,
Laun
,
H. M.
, and
Richter
,
H. J.
, 1996, “
MR Fluids With Nano-Sized Magnetic Particles
,”
Int. J. Mod. Phys. B
0217-9792,
10
, pp.
3167
3172
.
8.
Liu
,
J.
,
Flores
,
G. A.
, and
Sheng
,
R.
, 2001, “
In-Vitro Investigation of Blood Embolization in Cancer Treatment Using Magnetorheological Fluids
,”
J. Magn. Magn. Mater.
0304-8853,
225
, pp.
209
217
.
9.
Haghgooie
,
R.
,
Li
,
C.
, and
Doyle
,
P. S.
, 2006, “
Experimental Study of Structure and Dynamics in a Monolayer of Paramagnetic Colloids Confined by Parallel Hard Walls
,”
Langmuir
0743-7463,
22
, pp.
3601
3605
.
10.
Sinha
,
K.
, 2005, “
Large Scale Synthesis of Crystalline Magnetic Nanoparticles
,” MS thesis, Material Science and Engineering Department, University of Nevada, Reno.
11.
Carlson
,
J. D.
,
Catanzarite
,
D. N.
, and
St Clair
,
K.
, 1996, “
Commercial Magneto-Rheological Fluid Devices
,”
Proceedings of the 5th International Conference on Electro-Rheological Fluids, Magneto-Rheological Suspensions, and Associated Technology
,
W.
Bullough
, ed.,
World Scientific
,
Singapore
, pp.
20
28
.
12.
Wang
,
X.
, and
Gordaninejad
,
F.
, 1999, “
Flow Analysis of Field-Controllable, Electro- and Magneto-Rheological Fluids Using Herschel-Bulkley Model
,”
J. Intell. Mater. Syst. Struct.
1045-389X,
10
(
8
), pp.
601
608
.
13.
Gordaninejad
,
F.
,
Kavlicoglu
,
B.
, and
Wang
,
X.
, 2005, “
Friction Factor of Magneto-Rheological Fluid Flow in Grooved Channels
,”
Int. J. Mod. Phys. B
0217-9792,
19
(
7–9
), pp.
1297
1303
.
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